Wear-resisting alloy



. may be present in small amounts, as is the Patented May 3, 1927.

meant BURNEAM a. mean, or nouenas'ron, AND RUSSELL rnanxs, ornLMnnn-s'r, NEW roan, assrenons r0 HAYNES s'rnnnr'rn COMPANY, Aconroaarron or INDIANA.

WEAR-RESISTING- ALLOY.

No Drawing.

The invention is an alloy useful as a-material for makingarticlessubject to abrasive Wear, such as bearingsand gages, and for otherpurposes.

The alloy comprises as its essential constituents tungsten chromium,carbon, boron and iron; and silicon is a valuable constituent though notstrictly essential. The tungsten content is preferably between 1 percent and 12 per cent; the chromium between 25 per cent and 35 per cent;the carbon between 1.0 and 3.5 percent and the boron between 0.1 and 1.0per cent; with the remainder principally iron. Silicon is usuallypresent in such metals and alloys as are used in preparing the alloy ofthe invention and is therefore a normal constituent of the final alloy.lnr'nany cases it is advantageous to increase the silicon content beyondthe value at which the fortuitous sources of silicon referred to wouldfix it: for' example to bring the total silicon content to between 1.0and 3.0 per cent. Manganese also enters the alloy in small quantities asa'minor constituent of the raw materials, and manganese may beintentionally added as a deoxi-' dizer. Variousother metals andmetalloids case with the majority of alloys.

The hardness of the alloy increases as the tungsten and carbon areincreased within the range given, while diminishing the contents ofthese elements increases toughness.

Boron imparts strength and improves the grain structure and silicon to adecidedly less degree has a somewhat similar action. Either of theseelements if its proportion is unduly increased causes the alloy tobecome too brittle for the use contemplated. It will be obvious thatsince each ofthe elements mentioned has a tendency to producebrittleness if increased to its upper. limit, a proper balance betweenhardness and toughness will not be obtained by simuh' taneously usingall of the elements in maximum quantity.

A composition which is excellent for many pur ses contains tungstenabout 7.5

per cent; c omium about per cent; boron Application filed December 24,1925. Serial No. 77,575.

about 0.4 per cent; carbon 2.5 to 3.0 per cent; and siliconLO to 1.5 percent.- A specific alloy of about this composition contained:

Per cent. W 7.11 Cr 29.53 B 0.39 C 3.05 Si 1.50 Mn' 0.39

lhe Brinell hardness of cast bars of this alloy was 512 and thescleroscope hardness 64. The breaking strength in transverse of one-halfinch square cast bars held cantilever fashion with the load applied oneinch from the support was 2360 pounds.

The alloy may be made by melting together commercial metals and alloyscontaining suitable proportions of the-elements desired in the finalalloy, and no particular difliculty will be encountered in itspreparation. The materials may be, for example, ferro-chromium andterm-tungsten of suitable carbon content and a boron compound or alloysuch as boron-carbide, manganeseboron or chromium-boron. Approximatelyone-halt ofthe boron addedto the charge is recovered in the final alloy.Within the preferred range given the alloy is not read ily forgeable ormachinable. It can be cast without difliculty to the desired shape andfinished by grinding. N 0 heat treatment is necessary as the hardness ofthe alloy is developed at the time of solidification.

We claim:

1. A. ferrous alloy suitable for making articles subject to abrasion,containing tungsten 1 to 12 per cent; chromium 25 to per cent; boron0.10 to 1.0 per centgand carbon 1 to 3.5 per cent.

2.1%. ferrous allo suitable for making articles subject to a rasioncontaining, approximately: tungsten 7.5 per cent; chromium 30 per cent;boron 0.4 per cent; carbon 2.5 to 3.0 per cent; and silicon 1.0 to 1.5per cent.

v 3. An article of manufacture designed for a use wherein it is subjectto abrasion composed of an alloy containing tungsten tungsten 7.5 percent; chromium 30 per 1 to 12 per cent; chromium 25 b0 35 per cent;boron 0.4 per cent; carbon 2.5 to 3.0 cent; boron 0.10 to 1.0 per cent;and carper cent; and silicon 1.0 to 1.5 per cent.

bon 1 to 3.5 per cent. In testimony whereof, we aflix our signa- 5 4. Anarticle of manufacturedesigned for tures.

a. use wherein it is subject to abrasion eom- BURNHAM E. FIELD. posed ofan alloy containing, approximately: RUSSELL FRANKS.

